Stay tape



April 1953 J. E. BOULWARE ET AL 2,636,835

STAY TAPE 3 Sheets-Sheet 1 Filed Aug. 2, 1949 mm/Z31 April 28, 1953Filed Aug. 2, 1949 J. E. BOULWARE ET AL STAY TAPE 3 Sheets-Sheet 2 pf28, 1953 J. E. BOULWARE ET AL 2,636,835

STAY TAPE Filed Aug. 2, 1949 s Sheets-Sheet s R VEYmS Patented Apr. 28,1953 UNITED STATES PATENT OFFICE .tffiii. Jaz'n'esE. BouIware;Attlebor'o Falls, and William H. Cannard, Att'l'ehoro, Masst, assignorsto The Gummed Products Company, Troy. Ohio, a cor poration of OhioApplication August 2, 1949, Serial No.- 108,188

"This: invention relates to paper stay tape and is particularlydirected'to such a. tape having re inforcing giving tensile strength ina transverse direction.

The general object of the invention is to provide a stay tape of hightransverse tensile strength.

' A further important object of the invention is to provide a stay tapewith reinforcing giving added transverse tensile strength with the'reinforcing so located as to directly strengthen arti cles to which thetape is applied.

A further object-of the invention is to provide a stay tape havingreinforcing giving additional tensile strength both transversely andlongitudinally.

Paper stay tapes are commonly used for securing the corners of cardboardboxes, and in such use are known as box stays. The present invention isdesigned to-provide a stay tape ideally suited as a box stay. However;stay tapes have many other applications and the present invention isadapted for general'usage'.

Transversely reinforcing paper box'stay tapes have heretofore been madein laminated form with strand reinforcing embedded in asphalt ad hesivebetween two paper lies so arranged as'to give added transversetensilestrength to the tape. Usually such laminated tape'has the exposed faceof the paper underply gummed with" a moisturesensitive animal glueadapted on wetting to -adhesively secure the tape to box corners. Suchtapes can be provided without pre-gummingfor the application of adhesiveat the time the tape is to be applied to a box corner. Such laminatedtapes are'subject to two objections. First, the moisture-present atthetime the-tape isadhesively applied to a box corner is absorbed on thepap'er' underply and cannot evaporate off' du'e to the presence of theasphalt adhesive which bonds the two paper plies together; Such moisturemay remain indefinitely, particularly under reirigeration',- and soweakens the underply that the same is likely to tear away from a boxcorner; Such a failure also occurs under conditions where card-i boardcartons are stored under conditions of-rela tively high humidity.The'underply'ot a lanii hated tape usually falls by rupturing into twostrata, one of which remains bonded to the tape by the asphalt adhesiveand the other of which remains bonded. to the box through theadhesiveapplied to the underface.

The second objection referred to with rein-- forced laminated boxstay-tapes is that the strand re insd s ot di d s re et en. he, bocorner. Its strengthening action is dependent upon the abilit of thepaper underply to resist strata rupture and it further depends upon thebonding strength of both the adhesivethrough which the tape is bonded toa box corner and to the strength of the asphalt adhesive which em bedsthe reinforcing between the plies of the tape. The present invention isdesigned to avoid ob j'ections to prior laminated box stay tapes of thetype described and at the same time to providea tape of simpleconstruction; For box stay purposes and likewise for other purposes thestrand reinforcing is so arranged on the tape that it directlyreinforces a box or other article independently of the strength or thepaper tape and independently of the strength of its bond with the'tape'.

The characterizing feature of the invention is that strand reinforcingis transversely arranged at frequent longitudinal intervals On theunderface of a paper stay tape so as to be adapted to be directly bondedto article surfaces. Use of laminated paper tape is possible but asingle ply paper tape is preferred. The strand reinforcing is bonded tothe tape by suitable adhesive. The ad hesive which is to secure the tapeto an article may be omitted fromthe tape as supplied and ap plied as aliquid at the time the tape is to be secured to an article: Again, asuitable article bonding adhesive may be applied to the tape in thecourse of manufacture in the form of a dry film capable of beingsoftened to an adhering state at the time of use. In the latter case itis important that adequate adhesive film be obtained on the surfaces ofthe strand reinforcing to insure a proper bond thereof with an article.To this end the strand reinforcing should be nonabsorbent at the timethe adhesive filmis applied. This condition can be obtained by havingthe strand reinforcing impregnated with the adhesive by which it isbonded to the tape. Such tape bonding. adhesive provides a rough surfacecoat ing on the strand reinforcing and we find that after setting anadequate amount of the article bonding adhesive film will adherethereto.-

For the strand reinforcing textile threads of nylon.- or othersynthetic, fibers are preferred because of their long length fibercharacter and greattensile strength. Cotton: or other vegetable fiberthreads may also be employed. The size of. the thread may varyconsiderably depending upon the increased degree of transverse tensilestrength required for the tape on the basis of its usage and also uponthe individual tensile strength of the thread. For a box stay we havefound thata 420 denier nylon thread vis very satisfactory. Forequivalent strength we may employ a double strand of two 210 deniernylon threads. We have also had quite satisfactory results with boxstays employing only a single strand 210 denier nylon yarn. Asindicated, however, the denier and the tensile strength of the threademployed is subject to considerable variation and is not a criticalfeature of the invention The strand reinforcing is firmly bonded to thereinforcing tape by a suitable adhesive. Animal glue and othermoisture-sensitive adhesives can be employed but are not preferredbecause they are likely to soften and loosen the bond between the strandreinforcing and the tape when the article bonding adhesive is applied.Heat setting synthetic resin adhesives can be employed for bonding thestrand reinforcing to the tape, likewise latex emulsion adhesives, bothof which are moisture-resistant after setting. We have secured bestresults, however, with synthetic resin emulsion type adhesives, whichhave extremely strong bonding properties and when set aremoisture-resistant and permanently flexible. Pressure sensitiveadhesives are unsuitable because they remain permanently moist and haveinadequate bonding strength for present purposes.

The invention will be more fully understood from the illustrativeembodiments thereof in the accompanying drawings and the descriptionthereof to follow.

In such drawings:

Fig. 1 is a perspective view of a roll of stay tape embodying apreferred form of the invention;

Fig. 2 is a greatly enlarged cross section of the tape shown in Fig. 1;

Fig. 3 is a fragmentary cross section of a box with the stay tape ofFig. 1 applied to the corner thereof;

Fig. 4 is a fragmentary section taken on line 4-4 of Fig. 3;

Fig. 5 is an underface view of a section of stay tape according toanother form of the invention;

Fig. 6 is an enlarged cross section of the tape shown in Fig. 5;

Fig. 7 is a fragmentary cross section of a box showing the tape of Fig.5 applied to the corner and being taken on line l-! of Fig. 8;

Fig. 8 is a fragmentary section at line 8-8 of Fig. 7

Fig. 9 is an underface view of a section of stay tape employing amodification of the construction of tape shown in Fig. 1;

Fig. 10 is an enlarged cross section of the tape shown in Fig. 9;

Figs. 11 and 12 are enlarged fragmentary cross sections of stay tapewherein the reinforcing strands are relatively fiat instead of round;

Fig. 13 is an underface view of a section of stay tape according tostill another form of the invention;

Fig-14 is a fragmentary enlarged cross sectio of the tape shown in Fig.13; and

Fig. 15 is a fragmentary enlarged longitudinal section corresponding toFig. 14.

The stay tape shown in Figs. 1 and 2 comprise a single ply of aper tape20, preferably smooth kraft paper. Creped paper can also be employed. Tothe underface 2| of the tape is bonded strand reinforcing of textilethread arranged as a series of transversely extending lengths 22' atfrequent longitudinal intervals. In the form shown transverse lengths 22are formed of a continuous thread with the ends of adjacent lengthsjoined along lines somewhat inwardly of the side edges of the tape. Suchformation of the strand reinto paper tape by an adhesive 23. The threadis preliminarily thoroughly impregnated and coated with the. adhesive 23by immersion and then applied to the tape. Pressure is applied when theadhesive is partially set to insure a strong bond. Because of theapplied pressure the adhesive coating at the surface of the paper isflattened and spread. As before stated, it is preferred to use a resinemulsion type of adhesive. In the emulsion state the adhesive is ofcourse a liquid and may contain approximately 50% solids suspended inwater. After evaporation of the water when the adhesive sets and hardensa water resistant bond is obtained between the thread and the tape.

Because textile threads composed of a multiplicity of filaments areabsorbent impregnation thereof as above explained is desirable so thatadequate adhesive be present as a coating on the thread surface toinsure proper bonding with the tape. It is also found that impregnationmaterially increases the thread tensile strength, the adhesive bondingthe thread filaments to one another.

It should also be pointed out that the presence of the tape adheringadhesive on the threads is important when further adhesive is applied tobond the tape to an article. The latter adhesive is prevented fromabsorbing into the threads and. an adequate amount in the form of acoating or film will be obtained on the threads to insure their properbonding with an article. It is found that the tape bonding adhesivecoating on the threads has a somewhat rough surface, due at least inpart to the manipulation of the thread in applying it to the tape whilesuch adhesive coating is soft in a partially set state. Such roughsurface assists in adhering adequate article bonding adhesive to thethreads through cohesive action.

The advantage of having the reinforcing thread located on the exposedunderface of the stay tape will become apparent from Figs. 3 and 4.Therein a strip of the stay tape is applied to a corrugated cardboardbox corner to secure box sides 24 and 25. Preparatory to applying thetape to the box a coating of adhesive 26 is applied to the underface ofthe tape and the reinforcing thread and such coating adheres thereinforcing tape to the box. It will be apparent that the reinforcingthread is directly bonded to the surfaces of the box by adhesive coating26. Thus the transverse lengths of the thread directly reinforce the boxcorner, of course the tape is also bonded to the box by adhesive 26 sothat a strong composite structure is provided. However, the tensilestrength of the thread ordinarily exceeds that of the paper and thethread is the more important factor in securing the box.

Since the undersurface 2| of tape 20, as supplied, is uncoated it iscapable of absorbing moisture. This is advantageous in that whenadhesive 26 is applied at the time of installation of the tape on a boxor other article the water or other liquid can absorb into the paper andevaporate off of the outer surface. The ads hesive can dry more quickly.Itis preierabie that the same type of adhesive be employed to securethetape to the box as that which bonds the. thread 22 to the tape. Aresin type emulsioii'adhesive' is recommended. Hcwever where suchadhesive is employed. to: bondv the thread to the tapes or any otheradhesive which when set is} moisture resistant, any liquid cement havingstrong. bonding characteristics may be used to secure the tape to a boxor; other article.-

Paper tape 30 shown in Figs. througl'ifi is similar to that previouslydescribed. this case the undersurface 3| of thetape has reinforcingthread 32 bonded thereto by an. adhesive 33. Suchadhesive ispreliminarily applied to the tape as a film and the thread is thenapplied after such film has partially set. The thread is not itselfpreliminarily impregnated with adhesive as in the previous embodiment.

As before, adhesive 33 when set should be moisture-resistant. It is notintended as the adhesive for securing the tape to an article since itdoes not coat the major surface of thread 32. It is important, accordingto the invention, that the thread be bonded to the article as well asthe tape. It is further desirable, although not entirely essential, thatdislocation of the thread relative to the thread should be avoidedduring application to an article and this might occur if adhesive 33 wasof the character subject to softening when further adhesive to securethe tape to an article is applied.

Figs. 7 and 8 show tape applied to the outer surfaces of sides 34 and 35of a box corner. Bonding is effected by applying an adhesive layer 36which coats thread 32 and forms a second adhesive film on top ofadhesive film 33. Since film 33 prevents absorption of moisture throughtape 30 film 36 will not set as quickly as the article adhering adhesivefilm 26 shown in Figs. 3 and 4. It is preferred that film 36 be of thesame type adhesive as film 33, such as an'emulsion type of resin, butany strong bonding adhesive may be employed.

Stay tape 40 shown in Figs. 9 and 10 is similar to that of Figs. 1 and2. The undersurface 4| thereof is uncoated and reinforcing thread 42 ispreliminarily impregnated with adhesive 43 and applied to such surfaceafter the adhesive has partially set. The thread is applied as before inzig-zag arrangement to provide recurrent transversely extending lengths22'. Whereas for box stay purposes longitudinal reinforcement of thetape is unnecessary there are many other uses where longitudinal as wellas transverse reinforcement is desirable. In the present embodimentlongitudinal reinforcement is provided by longitudinal threads 44 and46. As in the case of thread 42 such threads are preliminarilyimpregnated with adhesive. Thread 44 is bonded by adhesive 45 to thetape somewhat inwardly of one edge thereof and also crosses and isbonded to lengths 42' of thread 42 near the ends thereof. Longitudinalthread 46 is provided with adhesive 41 which bonds the same to the tapesomewhat inwardly of the opposite edge and to the end portions of threadlengths 42'. At the time tape 40 is to be applied to an article asuitable adhesive will preliminarily be applied thereto in the samemanner as in the embodiment of Figs. 1 and 2. The arrangement ofreinforcing threads on tape 40 will give the same exceedingly high.tensile strength both transvers'ely and longitudinally;

Thereinfo-rci'ng threads may be; flattened out of their usual roundform. This may be: ac complished after the threads have been applied:the tape and. the: adhesive: has: partially set lay-applying relativelyheavy" pressure to the tape, as by means of a highly polished metalroll; In the embodiment of Fig. 1 1 paper stay tape 50 has reinforcingthread. 52' adhered there to by an adhesive film 53. In Fig. 12 tape tohas thread 62. adhered thereto by anadhesive coating 632- Such adhesive:is preliminarily ap plied-1. to' the thread as in the embodiment of-Fig.

l.= It will be understood that threads 52 and 62 lengths extendingtransversely of the' tapes: at frequent longitudinal intervals and. arepreferably applied as. a continuous lengthin zig-zag form in the samearrangement as previously. The flattening of threads 52 and 62 has theadvantage of presenting a greater surface area both for bonding to thetapes and bonding to articles upon application of further adhesive inthe form of a film on the undersurface of the tapes.

The form of the invention shown in Figs. 13 to 15 includes a dried filmof a softenable adhesive for bonding the tape to a box or other article.The paper tape 10 has bonded to it underface H transverse lengths ofthread 12. This is accomplished by preliminarily thoroughly impregnatingand coating the thread with an adhesive and applying it 'to the tapewhile still soft through adhesive coating 13, all as in the embodimentof Figs. 1 and 2. Such adhesive is preferably a resin emulsion or othermoisture-resistant type, although animal glues have been foundsatisfactory under some conditions. After such tape bonding adhesive hasdried, a film 14 of adhesive is applied to the coated thread 12 andentire underface of the tape and allowed to dry. Moisture-softeningadhesives such as animal glue have been found to produce a good bond ofboth the thread and tape to boxes and other articles which moistened atthe time of use. As already pointed out the non-absorbent and roughsurface provided on the thread by the tape bonding adhesive 13 insuresadequate article bonding adhesive film 14 on the threads to provide astrong bond between the thread and article.

It will be apparent that the invention provides extremely implereinforcing paper stay tape with greatly increased transverse tensilestrength. As before stated, the main advantage of the invention is thatreinforcing thread is bonded directly to the article so as to functionas a reinforcement therefor. The tape may be supplied in rolls as shownin Fig. 1 without danger of the adjacent convolution adhering to oneanother. The tape may be transported and handled under conditions ofhigh humidity without difficulty. The tape may be made up in a varietyof forms using paper of different types and weight, likewise withtextile reinforcing threads of various kinds and sizes. The scope of theinvention is to be determined according to the appended claims.

We claim:

1. A stay tape for securing and directly reinforcing the edges ofshipping containers consistmg of a strip of tape having strandreinforcement bonded to one surface of said tape and extendingtransversely over said tape surface in zig zag pattern, said strandreinforcement being impregnated with moisture resistant adhesive andbonded to said tape surface in flattened condition by said moistureresistant adhesive, and a coating of moisture sensitive adhesivecovering said tape surface and said strand reinforcement for bondingboth directly to a shipping container, said strand reinforcement beingburied in said moisture sensitive adhesive and adapted when bonded to ashipping container to directly reinforce the container independently ofsaid tape.

2. The structure claimed in claim 1 wherein said strand reinforcementcomprises nylon filaments.

3. A stay tape for securing and reinforcing the edges of shippingcontainers consisting of a strip of tape and strand reinforcement bondedto one surface of said tape by a moisture resistant adhesive, saidstrand reinforcement extending transversely over said tape surface inzig zag pattern, and a coating of moisture sensitive adhesiveconstituting the glue line-o1 said tape covering said strandreinforcement to bond both directly to a shipping container.

' JAMES E. BOULWARE.

WILLIAM H. CANNARD.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,195,430 Angier Aug. 22, 1916 1,197,315 Wendler Sept. 5, 19161,910,501 Schindler May 23, 1933 2,000,475 O'Donnell May 7, 19352,024,224 Humphner Dec. 17, 1935 2,070,624 Schlegel Feb. 16, 19372,098,909 Angier Nov. 9, 1937 2,311,572 Reynolds Feb. 16, 1943

1. A STAY TAPE FOR SECURING AND DIRECTLY REINFORCING THE EDGES OFSHIPPING CONTAINERS CONSISTING OF A STRIP OF TAPE HAVING STRANDREINFORCEMENT BONDED TO ONE SURFACE OF SAID TAPE AND EXTENDINGTRANSVERSELY OVER SAID TAPE SURFACE IN ZIGZAG PATTERN, SAID STRANDREINFORCEMENT BEING IMPREGNATED WITH MOISTURE RESISTANT ADHESIVE ANDBONDED TO SAID TAPE SURFACE IN FLATTENED CONDITION BY SAID MOISTURERESISTANT ADHESIVE, AND A COATING OF MOISTURE SENSITIVE ADHESIVECOVERING SAID TAPE SURFACE AND SAID STRAND REINFORCEMENT FOR BONDINGBOTH DIRECTLY TO A SHIPPING CONTAINER SAID STRAND REINFORCEMENT BEINGBURIED IN SAID MOISTURE SENSITIVE ADHESIVE AND ADAPTED WHEN BONDED TO ASHIPPING CONTAINER TO DIRECTLY REINFORCE THE CONTAINER INDEPENDENTLY OFSAID TAPE.